Convert TS to FLAC Online

TS-to-FLAC conversion is justified in use cases where preserving maximum audio quality takes priority over file size. There are four main scenarios: cultural archive preservation (recordings of concerts broadcast live on public TV or radio, historical interviews, documentaries with original soundtracks recorded on TV), where FLAC guarantees no additional degradation is introduced over the already-compressed audio of the original broadcast; forensic and legal analysis (examining broadcast quality, spectral analysis of recording authenticity, audio expert testimony in legal proceedings where chain of custody requires a lossless format); music production and mastering (recordings of live performances broadcast on TV or radio for subsequent use in live albums, requiring maximum quality for the mastering process); and technical broadcast quality comparison (comparative analysis of audio quality between different broadcasters or versions of the same content).

The quality of the resulting FLAC is entirely determined by the audio codec and bitrate of the original stream in the TS. For standard-definition (SD) European TV with MPEG-2 Audio Layer II at 192 kbps stereo: the FLAC will preserve exactly the original MP2 compression artifacts; the frequency response is limited to approximately 16 kHz (the MP2 encoder cutoff at 192 kbps). For HD TV with AC-3 5.1 at 384–640 kbps: the resulting FLAC (automatic stereo downmix unless otherwise specified) preserves the quality of the decoded AC-3, which at 640 kbps 5.1 is high quality for television. For DAB+ radio with AAC-LC at 128–192 kbps: FLAC quality is comparable to a CD for voice and music content. For TV channels with uncompressed PCM (rare, present in some premium satellite streams and professional broadcast channels): the FLAC will be truly lossless relative to the original.

TS-to-FLAC conversion has specific applications in the forensic and legal domain that justify the use of a lossless audio format. In legal proceedings where a TV or radio recording is presented as evidence, audio integrity is essential for expert testimony: a FLAC file allows a digital forensics examiner to compute the SHA-256 or MD5 hash of the decoded audio to verify it has not been altered between the original recording and its presentation as evidence; spectral analysis of a FLAC using tools like iZotope RX, Adobe Audition, or Audacity can detect edits, splices, or audio manipulations that would be harder to detect in a lossy format. Additionally, for files whose authenticity is questioned, comparing the FLAC of a TS recording with the FLAC audio of the live broadcast (if available) or with other recordings of the same event can reveal discrepancies indicating manipulation. The fact that FLAC preserves exactly the PCM decoded from the original codec — without the additional losses of lossy re-encoding — is fundamental for this type of analysis.

Most HD television channels broadcast via DVB-T2 use AC-3 (Dolby Digital) or E-AC-3 (Dolby Digital Plus) at 5.1 channels (left, centre, right, surround left, surround right, LFE/subwoofer). When converting to stereo FLAC, FFmpeg automatically performs a 5.1-to-2.0 stereo downmix using Dolby's standard mixing matrix: FL = L + 0.707×C + 0.707×Ls; FR = R + 0.707×C + 0.707×Rs (where C is the centre channel, Ls and Rs are the surround channels). The LFE channel is added to both channels at -10 dB. This downmix produces stereo compatible with all players but may sound different from the centred dialogue of the original mix (the centre channel is distributed between both channels). To preserve the original 5.1 audio without downmix in FLAC, multi-channel FLAC (5.1 FLAC) would be needed, which FFmpeg can generate but has more limited playback support than standard stereo FLAC.

Yes, and it's perhaps the most artistically valuable use case for TS-to-FLAC. Public and pay TV channels regularly broadcast live concerts: BBC Proms on BBC Two (the world's largest classical music festival, broadcast since 1895), Concerts de Paris on France 2 and France Musique, WDR Sinfonieorchester on WDR 3 (Germany), RAI Concerti on Rai 3 (Italy), and pop and rock concerts on general-interest channels. These concerts are typically broadcast with AC-3 5.1 audio at 384–640 kbps or, in more recent cases, Dolby Atmos. The audio mix quality of a television concert broadcast is generally comparable to a professionally produced live album (public broadcasters use professional audio recording systems with multiple microphones and studio-quality live mixing). Preserving the FLAC of these recordings allows playing them back at maximum quality for decades, using them as a high-resolution source for comparison with the commercial release of the concert (if it exists), or analysing them musically with spectral analysis tools.

Both TS-to-FLAC conversion and TS-to-MKA (Matroska Audio) remuxing are valid operations for extracting and preserving audio from a TS stream, but they have different characteristics. TS-to-FLAC involves decoding the original audio codec (MP2, AC-3, AAC) to PCM and subsequently encoding to FLAC: the result is always losslessly compressed PCM, regardless of the original codec, and produces a FLAC file that is universally playable on any modern audio player. TS-to-MKA (using stream copy without re-encoding) involves only extracting the original audio stream from the TS and encapsulating it in the Matroska container: it preserves exactly the original codec (AC-3 inside MKA, AAC inside MKA) without decoding or re-encoding, which is theoretically better for quality preservation, but the result is an MKA file with AC-3 or AAC that not all players recognise. For maximum compatibility with audio players, FLAC is superior. For maximum-fidelity technical preservation of the original stream, MKA with stream copy is superior.